Where should I look for the latest programming updates?
In general, Launchpad is where you can observe development happen. New code pushed to development branches, bugs being fixed, basically everything going on regarding elementary OS' codebase. You can also take a look at which branches are most recently updated and which bugs are updated most recently via Launchpad.
If you're interested in what the latest feature / bug fix update feels like, you could set up a VM or a dedicated system (whatever you have available) running with our daily repository. This repository gets new packages every day, as it daily builds the latest development branches for elementary OS' applications and services. You will encounter bugs and possibly untested software, so please DO NOT consider to run such an unstable system as a daily driver with important data on it. To run the daily repository, you'll need to add
ppa:elementary-os/daily to your repositories and fully update your system (
sudo apt-get update && sudo apt-get dist-upgrade).
Do elementary developers, designers, or supporters have blogs I can read?
There are very few people around the elementary OS team which are running a blog, and those are mostly unrelated to elementary OS itself. Sam Hewitt (a designer working on elementary OS) is running a blog, but as pointed out there is very few information about ongoing elementary OS development. I don't think there is anyone around who really blogs about recent elementary OS development.
Of course there is the official blog. It's both posting about important events happening (big features coming, new shiny versions, etc) and answering common questions (which are giving insight in decisions, bug fixes worked on, etc), but it's generally aimed at the normal users, so it's not very focused on ongoing development and technical speak.
Additionally, there are a few blogs out there who either focus on elementary OS or are supporting it by occasional entries about it. But these blogs are mostly following development on Launchpad and more often they are simply speculating about things without asking any team members before posting about it. Therefore, sometimes they're spreading misinformation and that's the reason I would not like to link them here.
Are there social media outlets that are actively being updated?
Beside the official blog I linked above, most information is on Google+. There is the official Google+ page which posts frequent updates (although it's linking blog entries as well of course), but both Daniel Foré and Cassidy James Blaede (which are basically the founding fathers of elementary) are posting about interesting stuff related to elementary OS (spiced up with personal opinion, of course). Last but not least, there is the official G+ community - developers occasionally post information about new elementary OS and third-party development.
Moreover, elementary runs two Twitter Accounts, @elementary and @elementaryfixes. The later one is posting whenever a bug on Launchpad is fixed.